Pneumatic action for pianos



LQH. PRAY.

PNEUMATIC ACTION FOR PIANOS. APPLICATION FILED IAN. I4 I92I 1,41 3,612.I I Patented Apr. 25, 1922.

UNITED STATES PATENT OFFICE.

LOUIS H. PRAY, OF MEDFORD, MASSACHUSETTS.

Specification of Letters Patent.

PNEUMATIC ACTION FOR PIANOS.

Patented Apr. 25, 1922.

original application filed August 1.0, 1920, Serial No. 402,648. Dividedand this application filed January 14, 1921. Serial No. 437,291.

T 0 all whom it may concern:

Be it known that I, Lorns H. PRAY, a citizen of the United States ofAmerica, and a resident of Medford, in the county of Middlesex and Stateof Massachusetts, have invented certain new and useful Improvements inPneumatic Actions for Pianos, of which the following is a specification.

This invention relates topneumatics for player pianos and has for itsobject the provision of a unit pneumatic which may be secured in anydesired position upon a supporting bar.

- The invention consists also 1n certain novel features ofconstructionand arrangement of parts which will be understood readily byreference to the description of the drawings and to the claims to behere inafter given. y

The present invention is a division of another application of mine filedAugust 10, 1920 and numbered 402,648.

For the purpose of illustrating the invention, one preferred formthereof is illustra ed in the drawings, this form having been found togive satisfactory and reliable results although it is to be understoodthat the various instrumentalities of which the invention. consists canbe variously arranged and organized and the invention is not limited tothe precise arrangement and organization of these instrumentali'ties asherein shown and described, except as required by the scope of theappended claims.

Of the drawings:

Figure 1 represents a side elevation of a unit embodying the principlesof the pres ent invention applied to a supporting bar shown in section.

Fig. 2 represents a vertical section of the same.

.In the drawings, 10 is a metal bar provided with a longitudinalV-shaped upward bend 11 extending longitudinally thereof.

The front edge of said baris provided with a downwardly extending flange12 while the rear edge thereof is provided with a downwardly extendingL-shaped flange 13.

Thls bar may be cut in any suitable length to accommodate it to variousstyles and sizes of ianos. i

ach end of the bar 10 is providedwith a slot '14 preferably extending tothe outer end thereof. 7

Positioned in the slot 1 1 is a clamping bolt 15 mounted in thehorizontal portion 16 of a bracket 17 having a vertical slot 18 therein.

cate it properly for the actuating parts of the piano action. a Byadjustmentof the supporting bar on the end brackets 16,17, the bar maybe accommodated to various lengths of pianos. :Vhen once adjusted thesupporting bar 10 is securely clamped to the horizontal portion 16 ofthe bracket 17 and the said brackets 17 are securely clamped to themembers 20 at the opposite ends of the piano. Only one end of the barand-its supportng bracket is shown in the drawings, it being believed tobe unnecessary to show the ent re length and the construction at theopposite end as this construction is simply a duplication. of theconstruction shown in Figs. 5 and 6 of the drawings.

The front flange 12 of the supporting bar 10 is adapted to be positionedin a trans verse slit 21 in the upper face of a block 22 while thehorizontal portion of the rear L- 1 and. 2 of the drawings, the pad 2!:is slightly compressed and thereby causes sufficient friction betweenthe two members to prevent one accidently moving relatively to theother.

By means of a screw or other holding member 25, a spring clip 26 securedto the upper face of the forward end of the block 22, this clipextending toward the rear of the block 22 and being adapted to engagewith the highest part of the V-shaped bend 11 thereby firmly retainingthe block 22 in position" on said supporting bar 10.

The blocks 22 may be adjusted longitudinally of the supporting bar 10and when moved into any desired position thereon they are retained insuch adjusted position by means of the spring clip 26 and the front andrear flanges 12 and 13.

lVhen it is desired to remove the block from the supporting bar, adownward pressure upon the front end of the block will cause thesprii'ig clip 26 to yield suliieiently to allow the front flange 12 tobe removed from the transverse slit 2]. and when said flange has beenremoved, a forward. pull upon the block 22 will disengage the block fromthe Lshaped rear flange 13.

It is obvious therefore, that the blocks 22 may be moved upon the siuporting bar into any desired position to accommodate them to the variousstyles of piano actions and retained in adjusted position withoutusingsecuring screws or other members which must be removed when it isdesired to remove a block for any reason.

Each block is a separate unit and may be removed from the supporting barwithout disturbing any of the other units and as means is providedwhereby such removal may be made toward the front of the piano, theother parts of the operating device will. not be disturbed.

The block 29 itself .is preferably made up of a plurality of layers ofmaterial.

The upper layer 27 of the block 22 is prov ided with a cylindrical port28 omiosite the f-shaped bend 11 in the supporting); bar 10.

Air is aiilaptcd to enter through the port 28 into a chamber 29 formedin the layer 30 immediately beneath the layer 27.

This layer 30 has also formed therein a passage 81 communicating withalined cylindrical openings 32 formed. in. the middle layer 38 and thelower layers 34-. and

The opposite end of the passage formed by said cylindrical openings 32communicates with a bellows or pneumatic hinged at 2-36 to the lowerlayer 35 and composed in part oi. a movable plate 37 connected to theedge of the lower layer by means of a. flexible member 38.

The rear end of the hinged movable plate 37 is provided with aprojecting member 39 adapted to communicate with and actuate a.

vertical rod for operating the hammer of the piano action.

In the layer 38 and alined with the port 28 is a connecting port L0, thelower end of which communicates with. a chamber 41 from the forward endof which extends a passage 4-2 communicating with a passage 4L3 in theupper end of which is a tubular member 4a, the upper end of which isadapted to receive a flexible tube 45 of rubber or some similarmaterial, the opposite end of which extends to and communicates with theusual vacuum chest.

The upper face of the lower layer is provided with a depression 46 withthe forward end of which communicates a passage 47. A tubular metal pipe48 communicates with the forward end of the passage l? and has an upwardbend therein the upper end. of which is adapted to receive one end of aflexible tube 49 of rubber or some similar material, the opposite end ofwhich communicates with one of the openings in the usual tracker board.

The upper end of the depression L6 is closed by a flexible diaphragm 50secured at its edge to the upper face of the layer 35 and superimposedupon this diaphragm 50 and preferably secured thereto is :1 stiffeningplate 51 having; an upwardly extending post 52, the upper end of whichprojects through the connecting port i0 with its extreme upper endslightly below the upper surface of the layer 33.

This layer 33 has extending upwardly therefrom, a plurality of guidepins between which is a disk valve 54, the upper and lower faces ofwhich are faced with rubber 55 as indicated in Fig. 2 of the drawings.

Between the passage i7 and the passage 42, is a port 56, the upper endof which is closed by a disl: 57 having a. small central vent as shownin l ies. 2 and 3 of the draw- 'ii'ig's.

This vent is so located that it can readily be cleaned of dust or anyother obstruct-ions by removing the rubber tube 45 from the tulmlarmember -lland extending a. needle downwardly through said tubular member.llinto the vent 58.

This is of some importance as devices of this class are liable to becomeinoperative by being; clogged with dust and it is desirable to providemeans for readily cleaning out the passages without disturbing the various operating parts.

liy making" the block 22 of a plurality of laminated layers, theconstruction of the block is greatly facilitated as each layer may bequickly pl'OVhlGtl with the various ports, chambers and depressions andthen all of the layers may be assembled and glued together making asuitable block.

When these layers have been thus secured ill] together, the sidesthereof have glued thereto, sheets59 of fibre-boarder some similarmaterial.

The operation of the deviceis as follows: A piano having been selected,the brackets 17 are secured to end frames 20 and ad justed vertically sothat the'su 'iporting bars 10 will be at the desired height and these.

A unitis then selected for each string of the piano and these aremounted upon the supporting bars 10 and adjusted lengthwise thereof sothat themember 39 of each unit will be in position to actuate a hammeractuating rod forming a part of the piano action.

The various units are then connected by means of the rubber tubes 45 and49 to the vacuumchest and the tracker board.

When thus connected and one of the openings in the tracker board isuncovered or exposed, air will be admitted to the tubular member 48 andpassing through the passage 47 and depression 46 will force'thediaphragm 51 upwardly and thereby cause the post 52 to lift the valve 54and close the port 28 while uncovering the port 40.

As ajconsequenc'e of this lifting of the valve 54, a communicatlon' fromthevac- "uum i chest is made through the tubular member 44, passages a3and 42, chamber 4L1, port 40, chamber 29, passages 31 and 32 to theinterior of the pneumatic or bellows 37- -38 secured to the lowerportionof the block 22. r

The. suction through these passages and chambers will thereupon causethebellows tobe collapsed and the projection 39 from the'rear end of theplate 37 will be consequeutly moved upwardly to actuate the hammer ofthe piano action.

When thetr'acker board opening is again covered the. neumatic or bellows3738 neath the diaphragm- 51 being discharged through the vent 58 thuspermitting the diaphragm 51' to move downwardly together with the post52. v

' The lowering of the post 52 will permit the valve 54 to drop into theposition indicated in Fig. 2 of the drawings and then atmospheric airwill pass through the port 28, chamber 29, passages 31, 32into the interior of the bellows or pneumatic 27-38 returning the plate 37 of saidpneumatic to its lowermost position as indicated in Fig. 20f thedrawings preparatory to. an-

' other operation thereof.

This makes a simple construction of unit effective.

which may be made economically and the means provided for mounting the--Vai1 ous units upon a supporting bar is most It is believed that fromthe foregoing description, the operation and manyadvantages of thepresent invention will be readily understood. 1 Having thus described myinvention, I claim I r l. A laminated pneumatic'unit constructed of aplurality of layers of material and provided with a plurality of airchambers and passages; valve mechanism therein controlling the passingof air through said chambers andpassages; a'bellows secured to the underpart of said block and communicating with one of said passages;- andside plates secured to said laminated block.

2. A pneumatic unit constructed of five layers of material the lowerlayer having a depression in its upper face communicating with anopening in the tracker board and the upper layer having an air inletport alined with said depression and the central layer havlng a portahned' with said upper port; a diaphragm closing the upper end ofsaicbdepression and having-a post extending upwardly therefrom throughthe lower port; a bellowssecured to the lower layer, achamberin the nextto the upper layer communicating with said bellows; a

'adiaphragmclosing the upper end of said depression and havinga postextending upwardly therefromthrough the lower port; a

bellows secured to the lower layer; a chamreturns to its normal positionthe air beber in-the next to the upper layer communi eating with saidbellows; a valve in said chamber normallyclosing the lower port andadapted by the upward"movement of said,

diaphragm to -be, forced upwardly to close the upper port; a series ofpins extending upwardly from the middle layer to prevent upper layerhaving an air inlet port alined with said depression and the centrallayer valve in said chamber normallyclosing the lower port and adaptedby the upward movehaving a port alined with said upper port; a diaphragmclosing the upper end of said depression and having a post extendingupwardly therefrom through the lower port; a bellows secured to thelower layer; a chamber in the next to the upper layer communicating withsaid bellows; a valve in said chamber normally closing the lower portand adapted by the upward movement of said diaphragm to be forcedupwardly to close the upper port; a walled chamber in the next to thebottom layer communicating with the vacuum chest; and a small ventbet-ween the communicating passages to vacuum chest and tracker bar.

5. A pneumatic unit constructed of five layers of material the lowerlayer having a depression in its upper face communicating with anopening in the tracker board and the upper layer having an air inletport alined with said depression and. the central layer having a portalined with said upper port; a diaphragm closing the upper end of saiddepression and having a post extending upwardly therefrom through thelower port; a bellows secured to the lower layer; a chamber in the nextto the upper layer communicating with saidbellows; a valve in saidchamber normally closing the lower port and adapted by the upwardmovement of said.

diaphragm to be forced upwardly to close the upper port; a walledchamber in. the next to the bottom layer communicating with the vacuumchest; and a small vent between the communicating passages to vacuumchest and tracker bar so located that it may be cleared fromobstructions without removal. of the unit.

I 6. A pneumatic unit constructed of live layers of material the lowerlayer having a depression in its upper face communicating with anopening in the tracker board and the upper layer having an air inletport alined with said depression and the central layer having a portalined with said upper port; a diaphragm closing the upper end o'l saiddepression and having a post extending up wardly there'trom through thelower port; a bellows secured to the lower layer; a chamber in the nextto the upper layer communicating with said bellows; a valve in saidchamber normally closing the lower port and adapted by the upwardmovement of said diapln'agm to be forced upwardly to close the upperport; pads of yielding material on opposite sides of said valve; and awalled chamber in the next to the bottom layer communicating with thevacuum chest.

7. A pneumatic unit provided with upper and lower chambers connected bya port and provided with an. air inlet port alined with said connectingport; a bellows secured thereto and communicating with the uppercluinnber; a pipe leading from the lower chamber to the vacuum. chest; adepression below the lower chamber; a. diaphragm separating saiddepression lirom'the lower chamber; a post extending upwardly from andmovable with said diaphragm, said post extending to the top of theconnecting port; a valve normally closing the connecting port andadapted to be forced upwardly to close the inlet port; and a pipe fromthe tracker board communicating with said depression.

8. A pneumatic unit provided with upper and lower walled chambersconnected by a port and provided with an air inlet port alined with saidconnecting port; a bellows secured thereto and communicating with theupper chamber; a pipe leading from the lower chamber to the vacuumchest; a depression below the lower chamber; a dia' phragm separatingsaid depression from the lower chamber; a post secured to said diaphragmand extending to the top oi? the con.- necting port; a valve normallyclosing the connecting port and adapted to be forced upwardly to closethe inlet port; resilient disks on opposite sides of said valve; and apipe from the tracker board. comnninicating with said depression.

9. A pneumatic unit provided with upper and lower chambers connected bya port and provided with an air inlet port alined. with said connectingport; a bellows secured thereto and communicating with the upperchamber; a pipe leading from the lower chamber to the vacuum chest; adepression below the lower chamber; a diapl'iragm sep aratiiiig saiddepression from the lower chamber; a post extending upwardly from andmovable with said diaphragm, said post extending to the top of theconnecting port; a valve normally closing the connectingpm't and adaptedto be forced upwardly to close the inlet port; a pipe from the trackerboard comnumicating with said depression; and parallel passages from thevacuum chest and tracker hoard pipes to the lower chamber and depressionand connected by a small vent.

.l.(l. A pneumatic unit provided with upper and lower chambersconnectcul by a port and provided with an air inlet port alined withsaid. connecting port; a bellows secured thereto and communicatii'igwith the upper chamber; a pipe leading from the lower chamber to thevacuum chest; a depression below the lower chamber; a diaphragmseparating said depression from the lower chamber; a post extending tothe top of the connecting port; a valve normally closing the connectingport and adapted to be forced upwardly to close the inlet port; a pipefrom the tracker board communicating with said depression; an. inclinedtubular member in said block to receive the flexible oipe from vacuumchest; and a small. vent beneath the inner end of said pipecommunicating with said depression.

11. A pneumatic unit provided with upper and lower walled chambersconnected by a port and provided with an air inlet' port alined withsaid connecting port; a bellows secured thereto and communicating withthe upper chamber; a pipe leading from the lower chamber to the vacuumchest; a depression below the lower chamber; a diaphragm separating saiddepression from the lower chamber; a post extending upwardly from andmovable with said diaphragm, said post extending to the top of theconnecting port; a valve normally closing the connecting port andadapted to be forced upwardly to close the inlet port; and a tubularmember projecting upwardly from the front end of said block andcommunicating with the said depression, the upper end of which isadapted to receive the end of a flexible pipe from the tracker board.

12. A pneumatic unit provided with upper and lower walled chambersconnected by a 'pression.

port and provided with an air outlet alined with said connecting port; abellows secured thereto and communicating at its larger end with theupper chamber; a pipe leading from the lower chamber to the vacuumchest; a

depression below the lower chamber; a diaphragm separatingsaiddepression from the Signed by me at 7464' Old South Bldg, this 12thday of January, 1921. r

LOUIS H. PRAY. Witnesses: V

WALTER E. LOMBARD, NATHAN C. LOMBARD.

